1. Field of the Invention
This invention relates to an improved pneumatic control system and control means therefor as well as to a method of making such a control system.
2. Prior Art Statement
It is known to provide a pneumatic control system comprising a pneumatic source, a pneumatically operated device that produces an output, and a control means for interconnecting the source to the device. The control means has an input means interconnected to the source and an output means interconnected to the device, the control means having set point means for selecting a desired output of the device. The control means has valve means for controlling the interconnection between the input means and the output means so as to regulate the pressure value in the output means. The control means has regulating means for operating the valve means to tend to produce an output of the device that corresponds to the selected output of the set point means.
It is applicants' belief that such prior known control system has the regulating means sensing the output effect of the pneumatically operated device and operates the valve means so as to produce a pressure value in the output means that is substantially equal to a pressure value that will cause the device to produce the selected output. For example, see Smith U.S. Pat. No. 3,540,461.